1. Field of the Invention
The present invention relates generally to container handling systems, and more specifically relates to a chassis conversion saddle or frame useable in container handling systems for transporting standard ISO intermodal containers. More particularly, the subject invention pertains to a chassis conversion saddle for a standard 40' ISO container trailer for converting the container trailer to allow it to carry a standard 20' heavily loaded intermodal container.
A standard 20' container trailer and tractor has a sufficiently short spacing between the axles thereof that, under standard interstate shipping regulations the 20' container can only be loaded to 19 metric tons. In contrast thereto, the larger spacing between the axles of a 40' container and trailer would enable a standard 20' container loaded thereon to carry 24 metric tons, thereby enabling the standard 20' container to carry heavier loads.
In shipping and commerce today, standard 40' ISO (International Standards Organization) containers are frequently transported by standard 40' ISO container trailers and tractors. The 40' ISO containers are secured to the trailers by four standard ISO corner castings on the four corners of the container which are engaged by four standard ISO twist locks on the trailers.
Similarly in shipping and commerce today, standard 20' ISO intermodal containers are frequently used to transport merchandise, and these standard 20' ISO intermodal containers are transported through and by intermodal facilities such as ships, railroads, trucks, etc. which are all designed to transport and handle the standard 20' ISO intermodal containers. The standard 20' ISO intermodal containers are designed to be secured by four standard corner castings on the four corners thereof which are engaged by four standard ISO twist locks.
It would be advantageous to be able to transport standard 20' ISO international containers by standard 40' ISO container trailers and tractors.
2. Discussion of the Prior Art
Glassmeyer U.S. Pat. No. 4,049,135 is fairly pertinent to the present invention, and discloses an arrangement for handling standard ISO air cargo containers which includes a chassis adapter frame connected to the chassis of a highway trailer by means of twist locks. The adapter frame includes twist lock assemblies which are adapted to engage the base of an air cargo container, whereby the adapter frame may be selectively removed from the container if desired. The arrangement includes loading and conveying arrangements which are particularly suited for transporting the air freight container with the adapter frame connected thereto or removed therefrom. Standard ISO air containers built to international standard dimensions have a rectangular box configuration of eight feet by eight feet by twenty feet. An important requirement for air cargo containers is that they must have a minimum tare-weight versus volume ratio. This is accomplished by constructing a container so that it is possible to leave the container underframe or base support structure on the ground when the container is loaded onto the airplane. The underframe is necessary when transporting the container by means of lift trucks or other loading devices, but the underframe is not necessary when the container is supported on the floor of an airplane. This patent pertains to a handling system whereby air containers and separable adapter or transporter frames are utilized in the transportation of the containers to the airplane, but are removed before the container itself is transported by means of roller conveyors into the interior of the fuselage of the plane. This patent provides for either the side transfer of containers from the adapter frame directly to a power conveyor system, or the side transfer of containers with the adapter frame onto a transfer device which has power rollers for raising the containers vertically from the adapter frame and thereby conveying the same into the airplane. The patent uses a transporter or adapter frame which is readily attached to the base of a container by means of twist lock assemblies. The adapter frame in turn is attached with a container fastened thereto to a trailer chassis by means of twist lock assemblies normally provided on such trailer chassis.
U.S. Pat. No. 4,537,540 discloses a transport frame for ISO standard containers which is intended to adapt the ISO standard to a particular freight handling system.
U.S. Pat. No. 3,690,485 discloses a pallet particularly adapted for handling air freight containers with a plurality of roller bearing members therein. The top portion of the frame is separable and may be used to adapt an air freight container to ISO standards.
U.S. Pat. No. 3,480,174 discloses a frame for adapting a plurality of smaller containers to ISO standards, which appears to be a 20' ISO frame having ISO standard twist locks.
U.S. Pat. No. 3,161,151 discloses a cradle for carrying standard ISO containers on a flat car to transport the containers in a railroad environment.
U.S. Pat. Nos. 3,342,522, 3,439,822 and 4,163,425 disclose modifications, such as moveable bolsters, to adapt a trailer chassis or truck chassis to carry or handle ISO standard containers. Each of these bolsters is a separable piece and it must be separately loaded and adjusted for each haul.
U.S. Pat. No. 2,958,538 discloses a frame which includes a jacking means for raising the container for engaging or disengaging a truck chassis.
U.S. Pat. Nos. 3,122,764, 3,881,207 and 4,209,869 disclose loading dock platforms or levelers which pivot up and forward to provide a transition zone between a truck and a loading dock.
U.S. Pat. No. 1,699,882 discloses structural details of a loading dock adaptor.